The present invention relates to power generating units such as compressors, electrical generators and welding power supplies, and particularly units of this type that can be transported to a work site.
Portable units that can be carried to a site are known, and a typical unit of this type, such as a TS 200, Model 5000 welder/generator sold by Burco/Mosa, includes an open, lightweight frame consisting of metal tubing on which is mounted an internal combustion engine directly connected to an alternator, which generates sufficient amperage to operate direct current welders and to provide some auxiliary alternating current for operating auxiliary equipment, such as a compressor that may be used to providing the compressed air needed to operate a plasma cutting torch used in conjunction with the welding equipment.
While units of this type operate satisfactorily, they have several disadvantages. First, and most importantly, even though the welder/generator or compressor are portable, it is nevertheless difficult and time consuming to load and unload, then connect up the various components which are included in the system. More specifically, in a typical operation, the portable welder/generator, which may weigh approximately 200 pounds, is lifted onto the bed of a pickup truck. Because it is so heavy, it is usually placed at the rear of the bed to avoid unnecessary lifting, and because it is so big, it creates an obstacle that makes it difficult to place any significant equipment in the pickup truck. Next, the compressor, which is a separate unit and also heavy (e.g. 150 pounds), must be lifted and placed on the bed of the pickup truck. At the job site, these units are generally unloaded from the truck, and in any event, they must be connected to one another, and with the welding and plasma cutting equipment, all of which is time consuming and often requires additional lifting of heavy equipment.
Moreover, even though the individual components of the system are relatively heavy, they nevertheless can be stolen and carried away from the back of a pickup truck, and therefore it is the general practice of those who use such equipment to unload and properly store the equipment in a secure location at the end of each working day, and again, this results is a significant amount of lifting of heavy equipment. The same is true for smaller, auxiliary tools that are used with these units, such as plasma cutters, mig welders and/or welding leads, all of which must also be removed from the truck and stored.
Finally, in such known units, the tubular frame in which the internal combustion engine and the alternator are carried is entirely open, and, as a result, workmen and others located near the equipment are constantly exposed to very high levels of noise resulting from the operation of the engine, the alternator, and the associated compressor unit.
Colella, U.S. Pat. No. 6,051,809, describes a welder/generator and compressor unit that is sized to fit in the bed of a pickup truck. Specifically, the unit has a generally T-shaped cross section, with a lower housing portion sized to fit between the bed walls of a standard pickup truck bed. The upper portion of the housing is somewhat wider, extending over and resting on the bed walls, thus forming the T-shape. On one end of the upper portion of the housing are controls for and connection to the welder generator and compressor. Within the housing are various components including an internal combustion engine, alternator, and air compressor, as well as an accumulator tank for storing compressed air produced by the compressor, a battery, electrical and compressed air connections, and a storage area. The engine, alternator and compressor are mounted in longitudinal alignment, with the drive shaft of the engine directly mechanically driving the shaft of the alternator and also mechanically driving the shaft of the air compressor through a speed-reducing pulley arrangement.
The Colella device has the advantage of being easily transportable in the bed of pickup truck, and having conveniently located controls and connections to permit use of all of the units without removal from the pickup truck. Furthermore, the enclosed housing provided in the Colella device allows for some reduction of noise.
Unfortunately, the device shown in the Colella patent has a number of drawbacks. First, there is no provision in the described device for storage of fuel for the engine. Presumably, a fuel tank would be provided within an unused portion of the housing or in the truck bed adjacent to the unit. In such a position, the tank would be difficult to access for refueling. Furthermore, in typical use, the Colella device would remain within the pickup truck bed at all times, therefore, when the fuel tank (wherever positioned) is refilled, spilled fuel would fall into the housing or truck bed soiling the bed or housing and creating a potential safety hazard. Similarly, the Colella patent does not describe a purge valve for the accumulator tank which would be needed to purge condensed water from the tank. Typically, such a valve is located on the tank. However, such a location would be inconvenient. Also, when a purge valve on the compressed air accumulator tank is opened to purge water from the tank, water is likely to be emitted into the housing, introducing unwanted moisture into the housing.
Second difficulty with the Colella design is that it is sized to fill the entire width of a pickup truck bed. As a consequence, the unit can only be readily installed adjacent the tailgate of the truck bed, to the rear of the wheel wells, for the reason that the width of the unit prevents sliding the unit past the wheel wells. Although, the unit may be lifted over the wheel wells to a forward position in a short bed truck, the unit may be required to be placed in a rearward position for the reason that a short bed truck permits insufficient space (only about one foot) for the Colella unit to fit between the wheel wells and forward end of the truck bed. Positioned in a rearward bed location, the unit limits other uses of the truck bed, as items must be lifted over the bed walls to be placed in the bed, rather than sliding those items into the bed via the tail gate. Furthermore, with the Colella unit in the truck bed, the length of the bed is shortened such that the bed may no longer accommodate typical construction materials such a plywood sheets.
A third difficulty with the Colella design arises when fitting the unit to pickup trucks of different makes and models. While there is, to a reasonable extent, a standard pickup bed width, there is no standard height for pickup bed walls. As a result, the intended fit of the Colella unit, to rest on the pickup walls, will likely be correct for only a certain class of pickups. When the unit is installed in other classes of pickups, it is likely to either rest on the floor of the truck bed with the upper housing sections inconveniently elevated above the top of the bed walls, or, alternatively, rest on the top of the bed walls but with a substantial gap between the bottom of the housing and the bed floor. In the former case, the housing floor would need to be designed to distribute weight, to prevent damage to either the unit or truck bed when the unit is resting on its bottom surface. The only way to avoid such issues would be to reduce the height of the lower housing of the unit to a height less than the shortest bed wall in which the unit might be used, which would reduce the volume of the housing available for the identified components.
In addition to the foregoing difficulties, there is the further complication that the total weight of the various elements called for the Colella patent can easily approach 800 pounds, exceeding the weight that can be supported by typical truck bed rails, and requiring substantial reinforcement of the upper housing portions to support the unit in the intended manner.
A further difficulty with the Colella unit arises from the manner in which elements are positioned within the housing. The longitudinal, mechanically coupled arrangement of the engine, alternator and compressor makes efficient use of the space; however, it hinders the efficient flow of cooling air to those elements since such units are typically designed to obtain or exhaust cooling air in the longitudinal direction, and each element is longitudinally abutting either another element or the housing and truck bed walls. As a consequence, cooling air flow may be restricted and/or heated air may be caused to flow from one unit onto another, limiting cooling.
Finally, the Colella unit, while portable, may have limitations in some environments where a pickup truck cannot be positioned close to the work area xe2x80x94for example, where welding is being performed deep within a structure, it may be inconvenient, or detrimental to weld power, to run long electrical leads carrying welder voltages and currents from an externally-parked pickup truck to the work site.
The present invention is directed to an integrated generator, compressor and welding power supply sized to fit within a pickup bed that improves upon the Colella unit by ameliorating the difficulties with the Colella unit that have been described above, and also enhancing features of the Colella device.
Specifically, in a first aspect, the invention features an integrated electrical and/or mechanical power generating unit, having a lower housing portion sized for placement within a pickup truck bed and an upper housing portion sized to extend over at least one bed wall. The housing contains an internal combustion engine for generating the electrical and/or mechanical power, and a fuel tank which is positioned in the upper housing portion. The fuel tank includes a filler orifice extending out of the upper housing portion such that fuel spilled when filling the tank has a flow path on the outside of the upper housing and an outside of the bed wall. This position of the fuel tank thus ameliorates spillage of fuel into the housing or bed as a consequence of refueling the tank.
In a second aspect, the invention features a portable compressed air generating unit, such as part of an integrated generator, compressor, and welding power supply, having a compressor and accumulator tank for storing compressed air, in which the accumulator tank has a purge orifice and a hose connected thereto leading to a remote manual purge valve and outlet. The manual purge valve may be conveniently located with the controls for the unit, and the outlet positioned in any convenient location outside the housing.
In a third aspect, the invention features an integrated electrical and/or mechanical power generating unit having a lower housing portion sized to fit between the wheel wells of a pickup truck bed and an upper housing portion sized to extend over at least one bed wall. Because the lower portion fits between the wheel wells, the unit may be readily slidingly positioned at any location in the bed, including a fully forward position, facilitating access to the remainder of the bed via the tail gate, or even a position directly between the wheels.
In a related aspect, the invention features an integrated electrical and/or mechanical power generating unit having a lower housing portion sized to fit within a pickup truck bed, and an upper housing portion sized to extend over at least one bed wall where the upper housing portion is adjustably mounted to the lower housing portion, so that the position of the upper housing portion may be changed either vertically or horizontally accommodate different makes or models of trucks, thus ameliorating difficulties raised by non-standardized sizing of truck bed walls.
In further related aspect, the invention features an integrated electrical and/or mechanical power generating unit having a lower housing portion sized to fit within a pickup truck bed, and an upper housing portion sized to extend over at least one bed wall, where the lower housing portion includes feet extending downwardly therefrom, to suspend a bottom side of the lower housing above the floor of the truck bed, and thereby permit access to the bed floor beneath the power generating unit for, e.g., a storage drawer or hauling elongated cargo such as plywood sheets.
In a further aspect, the invention features an integrated generator and compressor unit having a housing sized for placement within the bed of a pickup truck. Within the housing is an electrical power generating unit and an electrically powered compressor driven by electric power from the generating unit. By utilizing an electrically driven compressor, difficulties in mechanically coupling the generator drive to a compressor are ameliorated.
An additional aspect relates to improving the cooling of an integrated electrical and/or mechanical power generating unit, having a housing sized to fit within a pickup track bed. The unit comprises an air-cooled internal combustion engine having internal air flow passages, and an air cooled electrical or mechanical power converting unit (such as a generator or compressor) coupled to receive power generated by the engine and having internal air passages. The housing incorporates ducting to deliver cooling air to or from the internal air flow passages of the engine from or to an area outside of the housing, and further includes additional ducting to deliver cooling air to or from the internal air flow passages of the power converting unit from or to an area outside of the housing. In the specific embodiment, both an alternator and compressor are included and each is provided with such ducting.
Further aspects relate to improving the usability of an integrated electrical power generating unit through provision of connections. Here again, the power generating unit has a housing sized to fit within a pickup truck bed. In the first such aspect, the unit includes an internal generator generating three-phase alternating current electrical power, coupled to a three-phase connector external to the housing. Such a connection facilitates the work of crews such as elevator installers who primarily use tools needing three-phase power. In a related aspect, the integrated unit includes three-phase connectors for a welding power supply. The unit""s housing includes a closet space for receiving the welding power supply so that the welding power supply can be used when xe2x80x9cdockedxe2x80x9d inside the housing, or positioned remotely. This feature permits the welding power supply and its associated controls to be moved from location of the rest of the unit to a remote position more convenient to the work site.
The invention also features an integrated electrically and compressed air generating unit sized to fit within the bed of a pickup truck, in which the unit control panel includes electric power connections, compressed air connections, and pressure regulators for controlling generated compressed air. By including a pressure regulator in the control panel the need for external pressure regulation is ameliorated.
The above and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the invention.